Method for determination of adhesion of ice



Oct. 11, 1955 A. LIPPMAN, JR

METHOD FOR DETERMINATION OF ADHESION OF ICE Filed June 9, 1953 II II H Hll l m II CLAMP ////////////////g'% H ,f

III/I II/l/l/I/I/l/l/l/I/l/l INVENTOR.

ALFRED LIPPMAN JR.

BY 1 C film/w /owmmu ATTORNEYS United States Patent '0 2,720,106 METHOD FOR DETEREP/IENQTION F ADHESION Application June 9, 1953, Serial No. 360,493

4 Claims. (Cl. 73-15.6)

This invention relates to the measurement of the adhesive forces existing between ice and solid objects; more particularly the invention relates to apparatus for and methods of applying a shearing force between the ice and metal to achieve a quantitative determination of such force.

Heretofore the forces of adhesion existing between ice and metal have been determined, for example, by freezing a flat plateto an ice cube and then pulling the plate from the cube while providing for measurement of the pulling force. Such methods are dependent for accuracy upon the occurrence of a clean break at the interface between the ice and metal; however the ice itself in most cases tends to breakin the body thereof under the applied force, probably due to irregularities in the mass of discrete crystals which constitute the cube.

It is a primary object of this invention to describe a method of determining the adhesion between ice and metal which relies upon a shearing rather than a purely tensive stress.

It is an important object of this invention to describe apparatus for the exertion of a shearing stress between ice and metal.

It is a principal object of this invention to describe an arrangement for the measurement of adhesion between ice and metal which arrangement minimizes the possibility of separations within the body of the ice.

These and other allied objectives of the invention are attained by freezing a sliver in a body of ice and then so confining the body of ice while the sliver is being withdrawn therefrom that the withdrawing force is a measure only of the bonds of adhesion existing between the ice and sliver.

In the practice of the invention the sliver is suitably supported with a portion thereof extending into water in a container; the Water is then frozen and the resulting ice then is substantially completely confined having only the sliver protruding therefrom. A force is then applied to the sliver which force is directed along the axis of the sliver and the force is increased gradually until the sliver jumps or moves rapidly away from the ice; the force applied at the moment of separation is the measure of adhesion between the sliver and ice and will vary with the area of contact. Thus the larger the surface area of the sliver in contact with ice the more force it is necessary to apply to overcome the bonding.

It is to be particularly noted that in the practice of the invention the body of ice is supported against movement under the influence of the applied force; further, the body is so supported that the tendency to fracture or rupture along planes of cleavage or irregularities is overcome. Such failure in the other procedures of measurement occasions erratic results for when chunks of ice break within themselves and from the main body of the ice the force value attained is clearly an erroneous picture of the adhesion of the ice to the sliver.

Support in the case of this invention is provided by complete confinement of the ice save for the opening between 7 2,720,106 Patented Oct. 1 1, 1955 the sliver and container--which opening is so small as to have a negligible effect.

The invention will be more fully understood by reference to the following detailed description and accompanying drawing wherein the single figure illustrates one embodiment of the invention.

Referring to the drawing there is shown at 1 a metal re ceptacle in which there is a block of ice 3. Flange 5 of the receptacle is adapted to receive thereon a cover 7 which is provided centrally with an opening 9.

As shown in the figure a sliver 11 supported from a suitably fixed arm 13 extends into the ice. The arm 13 is utilized to support the sliver prior to the freezing ofthe water in the receptacle and is removed once the sliver is embedded in the ice.

In the process of invention the receptacle 1, with cover off as in the figure is filledwith water to an extent such that upon freezing the ice will just fill the receptacle to the-top of flange 5. If desired a wiper blade may be employed to continuously remove any ice formed above the level of the top of the flange. Alternatively if ice is permitted to form above the top shims or gaskets may be employed in conjunction with cover 9 to insure that the ice is securely retained prior to application of force F.

Further, the freezing of the water to ice preferably is effected by causing the ice to freeze from the bottom upwardly. This may be done by progressively cooling the "receptacle from the bottom upwardly; freezing may be initiated by seeding the water at the bottom with an ice crystal. This facilitates expansion of the water as the same freezes and undue stresses are not: placed on the container walls. In any event care should be taken that there is no confinement of water within the ice during freezing.

When the sliver 11 has been frozen into the ice the cover 7 which has been supported above the receptacle 1 in any convenient manner is lowered onto the flange and the ice and bolted to the flange. The sliver 11 is then released from the arm 13.

Thereafter force is gradually applied to the sliver in the direction indicated by the arrow at F. Any suitable scale arrangement may be utilized to measure the maximum force attained-which is the force at which the sliver parts from the ice. As mentioned hereinbefore this force is a function of the area of contact of the sliver with the ice and may be readily calculated to a unit basis.

The method and apparatus thus described provide a simple means for the accurate determination of important data as to the adhesion effects existing between ice and other materials; it is to be noted that outside influences play no substantial part in the operation. It is particularly stressed that should the ice tend to separate along a plane of cleavage or at a point of weakness within itself as at A in the figure that since the ice body cannot move such tendency will not affect the data or alter in any way the shearing force applied.

The invention has been described with specific reference to the adhesion existing between ice and metal as such as of primary importance; accurate data relating to such adhesive forces with regard to steel and aluminum are pertinent, for example, to high altitude flying. However, it is to be understood that any material which is of sutficient strength to withstand the force, as force F, without deformation, may be subjected to the practice of the invention.

It will be understood that this invention is susceptible to modification in order to adopt it to different usages and conditions and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. A method for the determination of the adhesion of ice to metal which comprises, supporting a sliver of metal partially within a body of water with a portion extending substantially vertically outwardly thereof, freezing the Water from the bottom upwardly to form ice and to confine a portion of the sliver therein, confining the body of ice substantially completely with only a sliver portion extending therefrom, and retaining the body of ice confined and fixedly positioned while applying a gradually increasing shearing stress to the metal, which stress is insufficient to cause the metal to deform, to cause the metal and ice to shear free of each other without substantial fracturing of the ice.

2. A method for the determination of the adhesion of ice to metal which comprises inserting a sliver of metal partially within a receptacle, filling the receptacle with water to completely cover the inserted portion of the sliver and to leave only an upper surface of the water exposed, freezing the water from the bottom upwardly to embed the sliver-in ice, substantially completely closing the surface of ice exposed while having a portion of the sliver protruding from the closed surface, and retaining the body of ice fixedly positioned and confined while applying a shearing stress to cause separation of the ice and metal without substantial internal fracturing of the ice.

3. A method for the determination of the adhesion of ice to metal which comprises supporting a sliver of metal partially within the body of water, freezing the water to formice and to confine a portion of the sliver therein, confining the body of ice substantially completely with only a sliver portion extending therefrom, retaining the body of ice confined and fixedly positioned While applying a gradually increasing shearing stress to the metal, which stress is insuflicient to cause the metal to deform, to cause the metal and ice to shear free of each other without substantial internal fracturing of the ice. I

4. A method for the determination of the adhesion of ice to solid objects which method comprises supporting a sliver of the solid object partially within an aqueous body, progressively cooling the aqueous body from the bottom upwardly to solidify the aqueous body and to confine a portion of the sliver therein, confining the solidified body substantially completely with only a sliver portion extending therefrom, retaining the solidified body confined and fixedly positioned while applying a gradual increasing shearing stress to the solid object, which stress is insuflicient to cause the solid object to deform, to cause the solid object and solidified body to shear free of each other Without substantial internal fracturing of the solidified body.

References Cited in the file of this patent UNITED STATES PATENTS 2,113,725 Goldman Apr. 12, 1938 2,129,043 Bortsch Sept. 6, 1938 2,182,082 Hayden et al. Dec. 5, 1939 FOREIGN PATENTS 378,498 Germany July 16, 1923 

1. A METHOD FOR THE DETERMINATION OF THE ADHESION OF ICE OF METAL WHICH COMPRISES, SUPPORTING A SILVER OF METAL PARTIALLY WITHIN A BODY OF WATER WITH A PORTION EXTENDING SUBSTANTIALLY VERTICALLY OUTWARDLY THEREOF, FREEZING THE WATER FROM THE BOTTOM UPWARDLY TO FORM ICE AND TO CONFINE A PORTION OF THE SILVER THEREIN, CONFINING THE BODY OF ICE SUBSTANTIALLY COMPLETELY WITH ONLY A SLIVER PORTION EXTENDING THEREFROM, AND RETAINING THE BODY OF ICE CONFINED AND FIXEDLY POSITIONED WHILE APPLYING A GRADUALLY INCREASING SHEARING STRESS TO THE METAL, WHICH STRESS IS INSUFFICIENT TO CAUSE THE METAL TO DEFORM, TO CAUSE THE METAL AND ICE TO SHEAR FREE OF EACH OTHER WITHOUT SUBSTANTIAL FRACTUREING OF THE ICE. 